Sensors for IoT and other uses were on display in Silicon Valley

Sensors are at the heart of the Internet of Things, collecting the data that powers wearables and smart cities alike. This week in San Jose, makers of sensors and related gear gathered for the Sensors Expo & Conference. Here's a look at some of these components.

The show was packed with more than 300 exhibitors. Unlike flashy IoT startups, many of these companies are small, family-owned operations. The sensors they make are good for a lot of different uses, including consumer, industrial and health applications.

This flex sensor from SpectraSymbol can detect bending motions and is used for things like patches that monitor the range of movement of an injured joint. The company makes several types of sensors for industrial, medical and consumer uses.

Imagine a needle in the center of this device, like the one in compass. Then picture it on the wing of a plane going up on its first test flight. This is a photodiode, and it could record every movement of the needle as the wind spun it around in different directions. Testers on the ground could view the data in real time, then make decisions about how to refine the wing before the next flight. Isorg, a French company, plans to start churning these out at full volume next year.

An iPhone has a fingerprint detector, but it's only designed to recognize one person and has to be taught just to do that. This detector from Isorg is precise enough to distinguish among millions of prints. It's already in use at border crossings where authorities are trying to identify specific individuals. The system doesn't capture or save an image of the print, just feeds the coordinates into an analytics platform in real time, Isorg says.

Sensors need to send data back to computers in a data center or a cloud. This kind of mesh network gear sends it without wires and can keep working even if some of the nodes die. It uses IEEE 802.15.4, a popular wireless standard that uses very little power. The maker isn't exactly a giant: B+B Smartworx, in Ottawa, Illinois, a division of a company called Advantech.

IoT can help companies run their data centers for less money. This temperature-sensing node using B+B SmartWorx technology has two little sensors at the tips of the cables. The Wzzard node can be mounted in the middle of a server rack with sensors at the top and bottom. Localized temperature data can show companies exactly where they can afford to turn down the air conditioning.

There are lots of ways to make music electronically, but most of them don't involve wooden keys and felt hammers. One company came to Hoffman+Krippner, a printed electronics maker, and asked for help making an electronic piano that uses traditional parts. The result was this design, where printed pressure sensors (the black strips on the top of the green circuit board) detect how hard each key is getting hit. The harder the impact, the louder the note.

When you hit sheet metal, it either dents or doesn't dent. Composite materials can suffer damage that's harder to see. Accelent's sensors detect where and how hard a composite panel has been hit (the green dot on the car's image marks the spot.) Understanding how much impact a given material can survive can also help aircraft designers find the right strength-to-weight ratio for new planes.

Inclinometers measure inclines, like the angle of a crane or of an airplane in flight. Rieker, a family-owned company in Pennsylvania, has been making them since 1917. Now it has an electronic model that is accurate to within one-tenth of a degree, even if it's in a very hot or cold place: Its temperature range is from -40 to +85 Celsius. That's 10 times as accurate as your average result with a smartphone, Rieker says.